<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <style>
        .box {
            width: 100%;
            height: 500px;
            display: flex;
            justify-content: space-between;
            flex-wrap: wrap;
        }

        /*.box div {*/
            /*width: 200px;*/
        /*}*/

        .box1 {
            width: 100px;
            height: 200px;
            background-color: pink;
            /* flex-grow: 1;占全部宽度的比例 */
            margin-right: 20px;
        }

        .box2 {
            width: 100px;
            height: 150px;
            background-color: purple;
            flex-grow: 2;
            margin-right: 20px;
        }

        .box3 {
            width: 100px;
            height: 250px;
            background-color: #a8dcff;
            flex-grow: 3;
            margin-right: 20px;
        }
    </style>
</head>
<body>
<div class="box">
    <div class="box1">盒子1</div>
    <div class="box2">盒子2</div>
    <div class="box3">盒子3</div>
</div>
</body>
</html>